1. Field of the Invention
This invention relates to an electronic instrument, and more particularly to an electronic instrument such as an electronic desk top calculator comprising various parts mounted between an upper case and a lower case.
2. Description of the Prior Art
Heretofore, such an electronic instrument, particularly an electronic desk top calculator (hereinafter referred to as the electronic calculator) has comprised parts such as an upper case, a lower case, an ornamental plate, a liquid crystal display device, an LSI circuit, a battery cell, a printed circuit substrate, etc., and has been assembled as by securing the ornamental plate to the upper case with adhesive, securing the printed circuit substrate having electrical parts such as the LSI circuit mounted thereon to the upper case from the inner side thereof by means of screws, and securing the lower case to the upper case by means of screws.
Thus, in conventional electronic instruments, the parts thereof have often been secured to one another by a plurality of methods such as securing with adhesives and fasteners, such as screws. These methods have lead to complicated assembly and also have detracted from the beauty of the instrument because the heads of screws used to secure the lower case to the upper case appear outside the instrument.